Any construction, regardless of its size, always begins with the development of the project. His goal is to design not only the appearance of the future structure, but also to calculate the basic thermal characteristics. After all, the main task of construction is the construction of strong, durable buildings capable of maintaining a healthy and comfortable microclimate, without extra heating costs. Undoubted help in the selection of raw materials used for the construction of buildings, will have a table of thermal conductivity of building materials: coefficients.
What is thermal conductivity?
Thermal conductivity is the process of transferring heat energy from heated parts of a room to less warm ones. Such an exchange of energy will occur until the temperature is balanced. Applying this rule to enclosing systems at home, one can understand that the process of heat transfer is determined by the period of time during which the temperature in the rooms is equalized with the environment. The longer this time, the lower the thermal conductivity of the material used in construction.
To characterize the conductivity of heat materials use such a thing as the coefficient of thermal conductivity. It shows how much heat per unit of time will pass through one unit of surface area. The higher this figure, the stronger the heat exchange, which means that the building will cool much faster. That is, when constructing buildings, houses and other premises, it is necessary to use materials whose heat conductivity is minimal.
Thermal conductivity of any material depends on many parameters:
- Porous structure. The presence of pores suggests heterogeneity of the raw materials. With the passage of heat through such structures, where most of the volume is occupied by pores, cooling will be minimal.
- Density. High density promotes closer interaction of particles with each other. As a result, heat exchange and the subsequent complete equilibration of temperatures occurs faster.
- Humidity. With high humidity of the ambient air or wetting of the walls of the building, dry air is forced out by droplets of liquid from the pores. Thermal conductivity in such a case increases significantly.
In the construction of all materials are conventionally divided into thermal insulation and structural. Structural raw materials have the highest thermal conductivity, but it is used to build walls, ceilings, and other fences. According to the table of thermal conductivity of building materials, when building walls of reinforced concrete, for low heat exchange with the environment, the thickness of the structure should be about 6 meters. In this case, the structure will be huge, cumbersome and will require considerable expenses.
Therefore, when erecting a building, special attention should be paid to additional heat insulating materials. A thermal insulation layer may not be necessary only for buildings made of wood or foam concrete, but even with such low-wire raw materials, the thickness of the structure should be at least 50 cm.
Need to know! Thermal insulation materials have a minimum thermal conductivity value.
When developing a construction project, it is necessary to consider all possible options and ways of heat loss. A large amount of it can go through:
- walls – 30%;
- roof – 30%;
- doors and windows – 20%;
- floors – 10%.
With an incorrect calculation of thermal conductivity at the design stage, the tenants are left with only 10% of the heat received from energy carriers. That is why houses built from standard raw materials: brick, concrete, stone are recommended to be further insulated. The ideal construction according to the table of thermal conductivity of building materials should be made entirely of insulating elements. However, low strength and minimal resistance to stress limits their applicability.
Need to know! When arranging the proper waterproofing of any insulation, high humidity will not affect the quality of the insulation and the resistance of the building to heat transfer will be much higher.
The most common option is the combination of the supporting structure of high-strength materials with an additional layer of insulation. These include:
- Frame house. When it is built with a wood frame, the rigidity of the whole structure is ensured, and the insulation is laid in the space between the racks. With a slight decrease in heat transfer in some cases it may be necessary to insulate also outside the main frame.
- House of standard materials. When making walls of brick, cinder block, insulation should be carried out on the outer surface of the structure.
This table contains the thermal conductivity of the most common building materials. Using such reference books, you can easily calculate the required thickness of the walls and the heater used.
Table of thermal conductivity of building materials: